I've heard a lot of talk around the number 8 for civil and mech, but again, it always changes based on demand.
I so far have actually found my years to be in reverse difficulty! 1>2>3>4... I hear 5th year has a bajillion projects though.
There has been *more* work, but it's been more manageable, I think because I had to learn how I worked and studied, etc... and now that I know myself I can do better!
Good luck